1. Field of the Invention
The present invention relates to a laser scanning control apparatus for forming a latent image on a latent image bearing member by scanning the latent image bearing member with a laser beam emitted from a laser light source.
2. Related Background Art
In general, in an image forming apparatus such as a laser beam printer or a digital copying machine, a semiconductor laser is driven with a laser beam driving circuit, a laser beam emitted from the semiconductor laser is modulated with an image signal, and a photosensitive drum is raster-scanned with the laser beam after the modulation using a rotating polygon mirror to thereby form a latent image.
At this time, in the apparatus having a plurality of semiconductor lasers, there is a problem in that the magnification of a latent image differs depending on the position on a photosensitive drum illuminated with the laser beams emitted from the respective semiconductor lasers. In addition, in the double-sided printable image forming apparatus, there is a problem in that heat of a fixing unit evaporates moisture contained in a sheet material so that a paper after fixing contracts in size, whereby even if ratios of the latent images on both the surfaces are identical to each other, the image sizes after printing are different from each other.
In contrast, there has been proposed a method in which, in order to obtain adjustment between them, an image clock signal with which image data is transferred is added at an arbitrary point to control the length between the image data to thereby correct the size of the image to be printed (refer to for example, Japanese Patent Application Laid-Open No. 2000-238342).
However, in the above-mentioned prior art, there is a possibility that since the image clock signal is corrected, the image data to be interpolated is fixed, and hence a space is generated in the position where the image clock signal is minutely lengthened to impair the printing quality.